Diablo III: Reaper of Souls

Interesting. It could simply be distance.
You're pretty damn far away from where the servers are hosted, while connections can be bounced all over the world, it doesn't change the fact that there's still going to be some processing time between you and the server.

If they can manage to get into the game, there'll be a vertical bar on the HUD, next to your resource meter, between the orb that your mana / whatever is stored in and the settings buttons.

That'll give latency information. If your ping is absurdly high, that'd be what the issue is.

Yeah, it seems like his connection is being specially stupid since last night.

EDIT: He didn't want to check if it was his internet but 15 minutes later he's so laggy he can't even get into Facebook or Team Speak to talk with me lol.